Restructuring Reserve Rollforward (Details) $ in Millions	9 Months Ended
	Jun. 30, 2017 USD ($)
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 142
Net accruals	198
Severance payments	(106)
Restructuring reserve, ending balance	234
Media Networks
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	36
Net accruals	136
Severance payments	(34)
Restructuring reserve, ending balance	138
Filmed Entertainment
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	12
Net accruals	47
Severance payments	(12)
Restructuring reserve, ending balance	47
Corporate
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	94
Net accruals	15
Severance payments	(60)
Restructuring reserve, ending balance	$ 49